1. Field of the Invention
The present invention relates generally to defibrillators and, more particularly, to a portable external defibrillator having user interface prompts to assist an operator of a defibrillator.
2. Related Art
Sudden cardiac arrest is a disruption of the heart's functioning that causes a lack of blood flow to vital organs. In a majority of instances, sudden cardiac arrest is manifested as an abnormal or chaotic heart rhythm, called fibrillation. These instances are generally identifiable by the victim's immediate loss of pulse, loss of consciousness and a cessation of breathing.
Sudden cardiac arrest has been attributed to over 350,000 deaths each year in the United States, making it one of the country's leading medical emergencies. World-wide, sudden cardiac arrest has been attributed to a much larger number of deaths each year. Unless immediate medical intervention is initiated, sudden cardiac arrest can lead to death within a matter of minutes.
There are four critical components of medical treatment that must be administered to a victim of sudden cardiac arrest: (1) early access to emergency care; (2) early cardiopulmonary resuscitation to keep the blood oxygenated and flowing to the victim's brain and other vital organs; (3) early defibrillation (the application of an electrical shock to the heart) to restore the heart's regular rhythm; and (4) early access to advanced medical care. When a person is experiencing sudden cardiac arrest, the electrical activity within the heart becomes chaotic. An electric shock from a defibrillator can reorganize the electrical impulses to allow coordinated pumping action to resume. To administer this shock, special pads from a machine called a defibrillator are placed on the victim's chest, and an electric shock is sent through the victim's body from one pad to another. As used herein, the term "pads" will include both pads and paddles.
If prompt cardiopulmonary resuscitation is followed by defibrillation within about four minutes, the victim's chances of surviving sudden cardiac arrest can approach or exceed fifty percent. Prompt administration of defibrillation within the first critical minutes is considered one of the most important components of emergency medical treatment for preventing death from sudden cardiac arrest.
Since prompt defibrillation is critical to survival, portable defibrillators have been developed that can be carried to the victim's location to defibrillate the victim prior to reaching a hospital. Initially, portable defibrillators were manual devices that could be used safely only by persons having a high level of medical training. Defibrillators with advanced decision making functions, called automatic external defibrillators or semiautomatic external defibrillators, have since been developed that can be used safely by emergency personnel with less advanced medical training. The term "automatic external defibrillator" will be used herein to include both automatic external defibrillators and semiautomatic external defibrillators.
Today, portable defibrillators are easy to operate and have built-in computers that guide users through the defibrillation procedure. These automatic external defibrillators can assess the patient's heart rhythm to determine whether defibrillation is necessary and, if defibrillation is required, will signal the operator to shock the patient. If a shock is not required, the defibrillator will not allow a shock to be administered to the patient.
Persons operating under the intense pressure of an emergency medical situation may forget a substantial amount of their training or may fail to understand the instructions being provided by the defibrillator. In rural areas, operators of defibrillators tend to have a low frequency of exposure to sudden cardiac arrest situations. Additional prompts can help them to remember their training. Also, there is a trend to place portable defibrillators in areas of hospitals not generally staffed with emergency personnel and in other public areas where difficult to reach arrhythmic patients are likely to be encountered, such as airplanes, airports, cruise liners, casinos, sports arenas and other populous facilities that are difficult or time consuming to access. An operator in this situation may have little or no training on operation of the particular defibrillator thus compounding the confusion and stress associated with resuscitating the victim.
To alleviate these sources of operation error, various instructional mechanisms have been developed to enable the defibrillator to prompt the operator during operation of the defibrillator in real time. One conventional technique for providing prompts has been to provide audio prompts in connection with text prompts displayed on the defibrillator display. Unfortunately, the limited amount of space available for displays and time constraints prevent the operator from reading a detailed description of the next action to be taken. Accordingly, it would be advantageous to have a defibrillator with an user interface capable of providing additional assistance to operators during deployment and operation of the defibrillator. Further, it would be advantageous to have a defibrillator that could start to neutralize adverse effects inexperience may have on operation of the defibrillator.